Inherited Chicks could someone help identify these 6-8 week old chicks?

[gobrown44]

Thanks for your help! Now I need to figure out the sex! The combs on the Speckled Sussex and the Columbian are quite developed at this point which would lead a rookie like me to believe they are roos. Any tips on sexing chickens?

 

[ramirezframing]

if you put up new pictures we can guess and tell you why we think so

 

[gobrown44]

Ok here's the latest pic of #3 about 8-10 weeks.